Natural gas in its native form must be concentrated before it can be transported economically. Liquefaction of the natural gas may be performed on land or off-shore in floating liquefaction plants. Floating liquefaction plants provide an alternative to subsea pipeline for stranded offshore reserves. The floating liquefaction plants include heat exchangers to cool the natural gas in the liquefaction process. One type of heat exchanger is the core-in-kettle, or core-in-shell, heat exchanger. The core-in-shell heat exchanger includes an outer shell partially filled with a refrigerant. At least one core is located in the outer shell and the natural gas is passed through the core. The refrigerant is also passed through the core to cool the natural gas while being maintained separate from the natural gas.
A core-in-shell heat exchanger is normally fed with a two-phase refrigerant mixture of liquid and gas. A distributor is provided in the outer shell to distribute the two-phase refrigerant. However, the flow of the two-phase refrigerant within the outer shell can result in mal-distribution of the two-phase refrigerant, and movement of the heat exchanger results in sloshing of liquid in the heat exchanger. Sloshing inside the outer shell has an adverse effect on the thermal function of the heat exchanger core.
In particular, conventional core-in-shell heat exchangers have a channel into which the two-phase refrigerant flows. The channel has slots or openings to distribute the two-phase refrigerant evenly or where desired in the core-in-shell heat exchanger. This configuration has functioned adequately in an on-shore environment, which is a stable environment. However, the configuration leads to a mal-distribution of the liquid in an offshore environment, where rocking or swaying of the core-in-shell heat exchanger leads to sloshing of the refrigerant. In particular, the sloshing of the refrigerant in the channel leads to the refrigerant entering the body of the heat exchanger in pulses and unevenly.